Plug



FIG. 1 is a front view of a plug, showing my new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a perspective view thereof.

The broken line portion of the figure drawings is included to show unclaimed subject matter only and forms no part of the claimed design. 

The ornamental design for a plug, as shown and described. 